<html>
    <head>
        <meta charset="utf-8">
        <title>Inject test</title>
        <script type="text/javascript">
            
            var pageVariable = "ok";
            var pageVariable2 = "ok";

            function modifyPageVariable() {
                pageVariable += "change by modify"
                pageVariable2 += "change by modify"
            }
            function modifyInjectedVariable() {
                injectedVariable += "change by modify"
            }
            function getPageVariable() {
                return pageVariable;
            }
            function getPageVariable2() {
                return pageVariable2;
            }
        </script>
    </head>
    <body>
        
        <p id="test">example</p>
        <ul id="list">
            <li>aaa</li>
        </ul>
    </body>
</html>